As a light emitting device comprising an electroluminescence (EL) light emitting layer formed with EL material, for example, an EL light emitting device which has a structure of laminating a substrate sheet, an electrode section, an insulating layer (reflecting layer), an EL light emitting layer, a top coat layer (epoxy type protective layer) in this order has been known (see, for example, JP-Tokukaihei-8-153582A).
In this EL light emitting device, a light emitting pattern according to one's preference can be formed by applying an alternating voltage between a fist electrode and a second electrode, and by forming a film of a transparent electrode with a predetermined shape on the top coat layer.
When water or humidity (water or the like) penetrates to reach the electrode section in the EL light emitting device, electrolysis may be generated at the electrode section or the breaking (damage) of wire due to the oxidation of the electrode may be caused. Also, since the first electrode and the second electrode are directly connected through water or the like, there is a safety hazard.
In this regard, in the EL light emitting device described in the reference document 1, the top coat layer functions as a waterproof layer to some extent. However, the top coat layer is exposed and the thickness of the layer is small, so that a part of the top coat layer is likely to be damaged by friction or the like. In this case, the above problem would be exposed.
To solve this, it is considered to thicken the top coat layer. However, when the top coat layer is thickened, the dielectric constant becomes small, thereby raising another problem to decrease the luminous intensity.
The present invention is accomplished in view of the problems, and an object of the present invention is to provided an EL light emitting device which is excellent in waterproof property, moisture-proof property and safety and can suppress the decrease of the luminous intensity as much as possible.